Desire
by Phoenix2312
Summary: Isabelle goes to the training room to let off some steam, she finds Lydia there and they decide to spar... However it turns out sparing is a lot more like foreplay for these too ladies... Sexy times ensure, set sometime after the wedding that wasn't. Lydia/Isabelle
**Desire**
 _One-Shot_

Isabelle turns the corner into the training room her eyes immediately taking in the girl already in working out. Lydia has her hair pulled back on a ponytail, her toned abs on full display. The grey sports bra and black leggings she's wearing cling to her body. Isabelle thinks she's been here awhile.

Soundlessly she enters the room, her eyes never moving from the other girl. She is fierce and deadly wielding her blade expertly. When one of the training dummy's falls to ribbons at her feet, Isabelle feels her throat go dry.

Lydia looks like a deadly avenging angel.

"Are you going to stand there staring or are you going to come train with me?"

Her voice is amused, and a little hoarse but she doesn't turn to look at Izzy, just sets down her blade and wipes the sweat from the back of her neck with a towel.

Isabelle climbs the three steps up to the training platform, tosses her water bottle on the table and moves into the centre.

"Want to spar?"

Lydia does turn around this time, and the smile on her face falters when she looks at the raven haired girl. Her eyes roam over the girl slowly, taking in every inch of her.

Isabelle smirks a little. Since she'd hit puberty at 13, she's seen hundreds of boys and girls look at her like this. Eyes lingering on the swell of her breasts or the flared curves of her hips. She can't say she doesn't enjoy it, it makes her feel powerful and sexy. It's why she dresses the way she does, she loves feeling this way.

Today is no exception, she's wearing a black sports bra with a zipper in the front which is undone a little ways. Her cleavage is ample and the tiny spandex shorts she's wearing leave little to the imagination.

But seeing Lydia looking at her this way, gives her an extra thrill, and a jolt in her lower abdomen.

The blonde must realise she's staring and busies herself for a few moments before turning back to Izzy.

"Ready?"

"Always."

* * *

Half an hour later they're still sparring.

They are pretty evenly matched and have both won several rounds. Its exhilarating. Fighting makes Isabelle's blood sing in her veins, lights her body on fire. Sparing with someone like this is almost intimate, for her sometimes it almost feels like a kind of foreplay. Which is why she always refuses to spar with Alec.

She thinks Lydia feels the same way because the blonde is getting noticeably more distracted. This time her eyes linger on the sweat glistening skin of Isabelle's stomach, in that split second hesitation she knocks the smaller girl to the floor and pins her there legs straddling her hips, forearm under her throat.

Lydia looks up at her with a slightly dazed expression, pupils dilated and dark.

Isabelle knows that expression too well. Arousal shoots through her like lightening, and she breaths hard, body pressing into Lydia's.

They stare at each other for a few long moments before Isabelle gives her a little smile.

"I win."

She takes her arm away from Lydia's neck, but doesn't move off of the girl. She watches her closely, she's breathing hard and her eyes move from Isabelle's lips to her neck, down to where her cleavage is spilling from the top of her bra.

Isabelle swears she sees Lydia lick her lips.

And now she's the one who's staring, Lydia's lips look so inviting, and the tension between them is palpable.

She feels herself leaning in and Lydia's eyes are fluttering closed... But suddenly there's a loud noise as Jace stomps into the room, banging the door open.

He doesn't seem to notice there awkward position, but Isabelle rolls over and up onto her feet before helping Lydia up.

"Have you guys seen Clary?" Jace nearly shouts at them.

"I haven't seen her since yesterday," Lydia says in a somewhat shaky voice.

"Last night she said she was going to breakfast with Simon so she's probably at Taki's" Isabelle tells him, trying to stay calm.

He doesn't say anything else, just stomps out of the room muttering profanities about vampires.

As soon as he's gone Isabelle wants to laugh, but suddenly the tension returns.

Isabelle feels a little awkward now, but she just clears her throat.

"Are you tired? You don't have to keep training with me if you are..."

She can hear the disappointment in her own voice.

But Lydia lets out a little laugh.

"It takes a lot more to tire me out..." Her voice isn't shaky any more, it's almost teasing. Isabelle looks at her, she's smirking and cocking one eyebrow.

"One More?"

"Definitely."

In mere seconds they're sparring again, this time with even more intensity than before.

Isabelle doesn't take her eyes off of Lydia's body, feeling desire building inside of her as they square off. She's never seen the other girl like this, like an animal stalking it's prey. It's making her brain fuzzy.

They're drenched in sweat and Isabelle's ponytail has fallen out, spilling loose waves over her shoulders.

After another 10 minutes Lydia has her cornered against the wall, her stomach pressing into the cold stone. She's breathing hard, heart pounding in her chest.

Suddenly there's a soft tickle on her ear. Hot breath that makes her shiver.

"Looks like I win this time."

Isabelle can't stop the little gasp that escapes her mouth when she realises Lydia's entire body is pressed up against hers.

Lydia chuckles and moves a step back.

Isabelle stays there for a moment, trying to calm her body. But the second she turns around the blonde is on her again.

Her eyes slam shut as Lydia kisses her with feverish abandoned. Her fingers grab at slim hips and Lydia takes it as permission to move in closer, pressing her farther into the wall.

It's hot, wanton and desperate, a clash of teeth and tongues. Lydia's mouth is demanding on Isabelle's drawing moans and whimpers from the back of the girls throat.

A rush of power and desire wash through Lydia's body. She loves being in control, and having the fierce Isabelle Lightwood at her mercy is intoxicating.

She wants to devour her, wants to hear her scream in pleasure and watch her come undone. Her brain is so filled with lust she doesn't even care that they're in the training room, absolutely exposed. In truth, it makes it hotter. Imagining someone coming in and seeing them like this, or them hearing Isabelle's cries of pleasure that are of her making.

She deepens the kiss for a few seconds before kissing down the girl's throat, sucking and biting the tender flesh, crazed with desire. But Isabelle doesn't seem to mind as she gasps out Lydia's name.

It's all the encouragement she needs. Lydia takes one of her hands and slides it in between their bodies over Isabelle's tight abs. She hesitates at the top of the girl's' shorts, playing with the waistband. Waiting for confirmation.

"Lydia. Please..."

She nearly comes right then and there from the desperation in Isabelle's voice.

Without hesitation she kisses her again and shoves her hand under the material, gasping against the girl's mouth when she feels smooth skin instead of panties.

With nimble fingers she slides through the girl's folds several times before circling her clit.

"Fuck Iz, you're so wet."

"God yes. It feels so good Lydia, don't stop."

She quickens her pace, and attaches her mouth to Isabelle's neck, sucking deep bruises into the skin. The raven haired girl writhes and moans from the combine pain and pleasure.

"Inside. I need you inside of me..." Her voice comes out whiny and desperate.

Lydia circles her dripping entrance twice before plunging two fingers into tight, wet heat. Isabelle cries out in pleasure.

The blonde works her fingers in and out finding a steady rhythm while the Izzy pulls out the tie holding her hair before burying her hands in the silky blonde locks, tugging roughly.

Lydia moves her mouth from Isabelle's neck to her ear.

"Fuck Izzy, you feel so good. I love seeing you like this, so hot and desperate. So naughty of you to let me fuck you right here in the training room where anyone could see us."

Isabelle cries out in pleasure again, her walls are starting to tighten. She's so close.

"You're mine now Isabelle. Mine and no one else's. Now come for me."

With one last pump of her fingers, she bites down hard into Isabelle's neck and the girl comes with a scream of her name.

It's the hottest thing Lydia has ever seen in her life. Exhausted the dark haired girl slumps in her arms, panting. She slowly pulls her fingers out and Isabelle groans at the loss. Keeping the girl upright with her free arm wrapped around a tiny waist, she brings her fingers to her mouth and sucks.

Isabelle's eyes fly open at the sound and she watches as Lydia tastes her.

"Mmmm you taste so good Izzy."

Isabelle's body shudders as one last pulse of pleasure rips through her at the words.

It takes them both several moments to catch their breath, but when they do Isabelle leans in and kisses Lydia hard.

"That was amazing. But I think we should find somewhere more private so I can have my turn. I can't let you have all of the fun, no matter how fucking hot that was."

Lydia just chuckles and kisses her again.

When she pulls away her eyes go to Isabelle's neck which is a mess of bite marks and bruises. It's so hot. But she's not sure the other girl will agree.

"As amazing as that sounds, perhaps I should give you an iratze... I might've gotten carried away. Not sure what everyone will do when they see that..." She indicates the girl's neck with an almost shy gesture.

Isabelle chuckles.

"Fuck that. Let them see. Then everyone will know I belong to you."

Another bolt of white hot arousal shoots through the blonde at the thought.

"Deal. Now about that 'fun' you promised me?"

Isabelle laughs, takes Lydia's hand and practically drags her from the training room.


End file.
